fix: upgrade multiple dependencies with Snyk

Snyk has created this PR to upgrade:
  - gatsby from 2.24.85 to 2.24.91.
    See this package in npm: 
  - gatsby-plugin-sass from 2.3.21 to 2.3.22.
    See this package in npm: 
  - gatsby-remark-autolink-headers from 2.3.14 to 2.3.16.
    See this package in npm: 
  - gatsby-transformer-remark from 2.8.46 to 2.8.47.
    See this package in npm: 
  - gatsby-transformer-sharp from 2.5.19 to 2.5.20.
    See this package in npm: 

See this project in Snyk:
https://app.snyk.io/org/github-newrelic/project/ee280047-f651-440a-aaec-462aac2b4fe2?utm_source=github&utm_medium=upgrade-pr

package.json

@@ -13,7 +13,7 @@
     "classnames": "^2.2.6",
     "date-fns": "^2.16.1",
     "diff": "^4.0.2",
-    "gatsby": "^2.24.85",
+    "gatsby": "^2.24.91",
     "gatsby-image": "^2.4.20",
     "gatsby-plugin-emotion": "^4.3.14",
     "gatsby-plugin-layout": "^1.3.12",
@@ -24,15 +24,15 @@
     "gatsby-plugin-offline": "^3.2.32",
     "gatsby-plugin-react-helmet": "^3.3.12",
     "gatsby-plugin-robots-txt": "^1.5.3",
-    "gatsby-plugin-sass": "^2.3.21",
+    "gatsby-plugin-sass": "^2.3.22",
     "gatsby-plugin-sharp": "^2.6.43",
     "gatsby-plugin-sitemap": "^2.4.17",
     "gatsby-plugin-use-dark-mode": "^1.1.2",
-    "gatsby-remark-autolink-headers": "^2.3.14",
+    "gatsby-remark-autolink-headers": "^2.3.16",
     "gatsby-remark-images": "^3.3.34",
     "gatsby-source-filesystem": "^2.3.35",
-    "gatsby-transformer-remark": "^2.8.46",
-    "gatsby-transformer-sharp": "^2.5.19",
+    "gatsby-transformer-remark": "^2.8.47",
+    "gatsby-transformer-sharp": "^2.5.20",
     "js-cookie": "^2.2.1",
     "node-fetch": "^2.6.1",
     "node-sass": "^4.14.1",